Another firefighter suffered critical injuries after fire crews arrived to investigate a gas leak in downtown Sun Prairie about 6:30 p.m. Tuesday and several buildings exploded, igniting a fire that sent billowing smoke that could be seen for miles around.

Four other firefighters, a police officer and seven civilians suffered injuries, according to Sun Prairie Police Lt. Kevin Konopacki. The firefighter who was critically injured has been stabilized, Konopacki said.

WE Energies spokeswoman Amy Jahns said workers for a private contractor punctured a 4-inch gas main, causing a leak that resulted in the explosion that rained debris around the downtown area and ignited vehicles parked in the area.

Authorities evacuated a half-mile radius around the center of the explosion. The Barr House and Glass Nickel Pizza exploded after the gas ignited, police said.

The Red Cross assisted evacuees at a shelter set up at Sun Prairie High School.

Steve Owen, 60, who owns Sun City Cyclery and Skates in downtown Sun Prairie, said he saw firefighters and police officers on the street and then the explosion happened. He said the building across from his shop "literally lifted up."

He said the force of the blast knocked him back in his chair and that he ran outside and saw a ball of fire.

"People were scrambling," said Owen, who lives above his shop.

Jill Thompson, 56, who lives about two blocks away, said she saw smoke immediately after the blast occurred.

"It shook the whole building," Thompson said. "I thought someone had hit the building with their vehicle."

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